The present invention is directed to an apparatus and method for treating contact lenses. More particularly, the invention is directed to a stand-alone apparatus and method for using same by which contact lenses can be cleaned. In a particularly advantageous form, the apparatus is single-use and disposable, and comprises a housing including a pair of closable liquid sealed containers sized and shaped to accept and retain a lens therein such that the lens is brought into contiguous wetted contact with a reactive layer during the treatment process.
Contact lenses have come into wide use for correcting a wide range of vision deficiencies or cosmetic use. Typically, such lenses are formed from a thin transparent plastic material shaped and dimensioned to fit over the cornea of the eye. The lenses have an optical surface that includes a concave interior first optical surface for contact with the eye, an opposed and optically associated convex exterior second optical surface, and a surrounding edge. The two surfaces together define a corrective lens medically prescribed for a particular eye.
Depending on the polymer material used to construct the lenses, the lenses may be either “hard” or “soft”. Hard contact lenses, which are comparatively more rigid, are typically formed from a relatively hydrophobic material such as polymethyl methacrylate (PMMA). Soft contact lenses, which are comparatively more pliant, are typically formed from a relatively hydrophilic polymer such as hydroxyethylmethacrylate (HEMA), which has the property of being able to absorb and bind a proportionately large amount of water within the polymer network. Soft contact lenses formed from such hydrophilic polymers, when hydrated, are more comfortable to wear than hard lenses because they conform better to the cornea of the eye and cause less irritation when worn for extended periods. For this reason, the great majority of contact lenses presently being prescribed are of the soft type.
Unfortunately, soft contact lenses while being worn may collect contaminants from the eye and its environment. These contaminants, for example, may include proteins and lipids, including denatured ones, from the tear fluid of the eye, and foreign substances such as cosmetics, soaps, airborne chemicals, dust and other particulate matter. Unless periodically removed, these contaminants may cause abrasion to the surface of the eye, may impair the visual acuity of the lens, and may serve as a nutrient media for potentially harmful microorganisms.
Furthermore, for wearing comfort it is necessary that soft contact lenses be maintained uniformly wetted at all times. While on the eye, the moisture content of the hydrophilic material of the lenses is maintained by tear fluid. However, when the lenses are removed for an extended period, as for cleaning or while sleeping, the lenses may dry out and become irreversibly damaged unless they are externally hydrated.
Consequently, various apparatus and methods have been developed for cleaning and hydrating soft contact lenses. For example, cleaning apparatus has been provided wherein the lenses are submersed in a variety of liquid cleaning agents, such as surfactants, oxidants, disinfectants, enzymatic cleaners, or abrasives. Other cleaning apparatus has been provided which included mechanically operated or electrically powered components for vibrating, rotating, abrading, scrubbing, heating, agitating, subjecting to ultrasonic energy, or otherwise mechanically manipulating the lenses to enhance the cleaning action of the cleaning agent.
Such prior apparatus and methods have not been entirely satisfactory for various reasons, including lack of cleaning effectiveness with respect to certain of the various contaminants found on the lenses, undesirable complexity, excessive time required for use, harshness to the lens material, and dependence on an external power source.
One apparatus which overcomes these shortcomings is described in U.S. Pat. No. 5,657,506, the disclosure of which is incorporated by reference herein. The apparatus utilizes a two-piece lens container wherein the exposed surfaces of two sponge members, wetted with an opthalmologically compatible solution, and each having thereon a reactive layer formed of a highly porous non-abrasive relatively polymeric material such as polytetrafluoroethylene (PTFE), are brought into compressive engagement with the optical surfaces of an interposed contact lens whereby the reactive layers cause contaminants to migrate from the lens to the reactive layers. Alternate apparatus are also disclosed in U.S. Pat. No. 6,138,312, the disclosure of which is incorporated by reference herein.
The present invention is directed to alternate constructions from those described in U.S. Pat. Nos. 5,657,506 and 6,138,312.
Accordingly, it is a general object of the present invention to provide a new and improved apparatus for cleaning contaminated contact lenses.
It is a more specific object of the invention to provide an apparatus for cleaning contaminated contact lenses which is simple to use and economical to manufacture.
It is a further object of the present invention to provide a disposable single-use apparatus for cleaning contaminated contact lenses having closable liquid-sealed container within which the lenses are contained while being cleaned.
It is a further object of the invention to provide a self contained apparatus for cleaning a contaminated contact lenses wherein the optical surfaces of the lenses may be received in a wetted environment in contiguous contact with a reactive medium whereby lenses can be generally cleaned without the application of abrasive force (e.g. without the force caused when rubbing the lens by hand).